M-Series Technical Manual
37
Cambridge Engineering, Inc.
SETTING TEMPERATURES
The Electronic Thermostat requires two temperature set-
tings. When the temperature drops below the HEAT ON
setting, the heater will turn on. When the heater raises
the space temperature above the HEAT OFF setting, the
heater will turn off. This difference provides an adjust-
able range of operation for the heater which minimizes
temperature swings.
The minimum run time and off time for the heater
regardless of temperature are both set at 2 minutes. The
allowable temperature range is 40°F to 99°F. The HEAT
OFF temperature can not be set lower than the HEAT
ON temperature.
1. Press and hold the
HEAT ON
button while pressing
the
UP
or the
DOWN
button until the desired tempera-
ture for the heater to turn ON is displayed.
2. Press and hold the
HEAT OFF
button while pressing
the
UP
or the
DOWN
button until the desired tempera-
ture for the heater to turn OFF is displayed.
TEMPERATURE CALIBRATION
To compensate for lead wire resistance, it may be neces-
sary to make an adjustment to the displayed temperature
to correct it to the temperature measured at the thermis-
tor sensor. The calibration feature allows the displayed
temperature to be offset either above or below the actual
sensed temperature. Be sure to use an accurate tempera-
ture meter for making this correction.
1. Press and hold the
HEAT ON
and
HEAT OFF
buttons
while pressing the
UP
or the
DOWN
button until the
correct temperature is displayed. ( A period [.] after
the temperature will indicate the Calibration Mode).
2. Pressing the
UP
or the
DOWN
button will display the
current calibration difference above or below (-) the
measured temperature.